Prostate-specific membrane antigen-targeted photosensitizers for photodynamic therapy

ABSTRACT

Urea-based photosensitizers, which target prostate-specific membrane antigen (PSMA) for imaging and targeted therapy of PSMA-expressing tumors and cancers are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 35 U.S.C. § 371 National Stage Entry ofInternational Application No. PCT/US14/060461 having an internationalfiling date of Oct 14, 2014, which claims the benefit of U.S.Provisional Application No. 61/890,600, filed Oct 14, 2013, the contentsof each of the aforementioned applications are herein incorporated byreference in their entirety.

BACKGROUND

Photodynamic therapy (PDT) is a minimally invasive cancer treatment andhas been used in clinic to improve cancer patients' quality of life andsurvival time. The lack of specific delivery of the photosensitizers,however, is a significant limitation of PDT. Non-targeted, conventionalphotodynamic therapy cannot deliver the photosensitizers specifically tothe tumor and the photosensitizers often circulate in the body longafter treatment and cause sensitivity to light for several months.

SUMMARY

In some aspects, the presently disclosed subject matter provides acompound of formula (I):

wherein: Z is tetrazole or CO₂Q; each Q is independently selected fromhydrogen or a protecting group; n is an integer selected from the groupconsisting of 1, 2, 3, and 4; R is H or C₁-C₄ alkyl; L is a linkergroup; and X is H or a photosensitizer moiety; or a pharmaceuticallyacceptable salt thereof.

In other aspects, the presently disclosed subject matter provides afluorescence imaging agent comprising a compound of formula (I).

In yet other aspects, the presently disclosed subject matter provides amethod for treating a prostate-specific membrane antigen(PSMA)-expressing tumor or cell, the method comprising administering atherapeutically effective amount of compound of formula (I) to a subjectin need thereof.

In still yet further aspects, the presently disclosed subject matterprovides a method of monitoring a target uptake or a response to therapyfor treating a PSMA-expressing tumor or cell, the method comprisingadministering an effective amount of a compound of formula (I) to asubject in need of treatment thereof, and measuring a fluorescencethereof.

Certain aspects of the presently disclosed subject matter having beenstated hereinabove, which are addressed in whole or in part by thepresently disclosed subject matter, other aspects will become evident asthe description proceeds when taken in connection with the accompanyingExamples and Figures as best described herein below.

BRIEF DESCRIPTION OF THE FIGURES

Having thus described the presently disclosed subject matter in generalterms, reference will now be made to the accompanying Figures, which arenot necessarily drawn to scale, and wherein:

FIG. 1 shows a general schematic of the presently disclosed urea-basedphotosensitizers;

FIG. 2 shows representative linkers for use with the presently disclosedurea-based photosensitizers;

FIG. 3 shows representative photosensitizer moieties for use with thepresently disclosed urea-based photosensitizers;

FIG. 4 is whole body (left) and ex vivo organ (right) imaging of mousewith PSMA+PC3 PIP and PSMA-PC3 flu tumors at 24-h post injection of 10nmol of YC-9;

FIG. 5 shows YC-9 efficiently and specifically kills PSMA-expressingcells in vitro; and

FIG. 6 is whole body (left) and ex vivo organ (right) imaging of mousewith PSMA+PC3 PIP and PSMA-PC3 flu tumors at 24-h post injection of 50nmol of YC-6.

DETAILED DESCRIPTION

The presently disclosed subject matter now will be described more fullyhereinafter with reference to the accompanying Examples and Figures, inwhich some, but not all embodiments of the presently disclosed subjectmatter are illustrated.

The presently disclosed subject matter may be embodied in many differentforms and should not be construed as limited to the embodiments setforth herein; rather, these embodiments are provided so that thisdisclosure will satisfy applicable legal requirements. Indeed, manymodifications and other embodiments of the presently disclosed subjectmatter set forth herein will come to mind to one skilled in the art towhich the presently disclosed subject matter pertains having the benefitof the teachings presented in the foregoing descriptions and theassociated Examples and Figures. Therefore, it is to be understood thatthe presently disclosed subject matter is not to be limited to thespecific embodiments disclosed and that modifications and otherembodiments are intended to be included within the scope of the appendedclaims.

I. Prostate-Specific Membrane Antigen-Targeted Photosensitizers forPhotodynamic Therapy

The presently disclosed subject matter provides urea-basedphotosensitizers (FIG. 1), which target prostate-specific membraneantigen (PSMA). PSMA is a type II integral membrane protein that isabundantly expressed in prostate cancer and endothelium ofneovasculature in most solid tumors. These characteristics make PSMA anexcellent target for imaging and targeted therapy for these cancers.

The presently disclosed PSMA-targeted photosensitizers include threefunctional parts: (1) a photosensitizer; (2) a PSMA binding ligand; and(3) a linker that tethers the PSMA binding ligand to thephotosensitizer.

Lysine-glutamate-urea serves as a tumor-homing molecule that guides thephotosensitizer to the PSMA expressing tumor cells. Referring now toFIG. 2, the linker, which is used to improve the pharmacokinetics invivo, can be, but is not limited to: lysine-suberate (as in compound 1),polyethylene glycol (PEG, as in compound 2), and PEG-lysine-suberatelinker (as in compound 3). Further, the photosensitizers moieties canbe, but are not limited to, the moieties provided in FIG. 3.Representative PSMA-binding ligands are disclosed in International PCTPatent Application Publication No. WO2010/108125 for “PSMA-TargetingCompounds and Uses Thereof,” to Pomper et al., which is incorporatedherein by reference in its entirety.

A. Compounds of Formula (I)

In some embodiments, the presently disclosed subject matter provides acompound of formula (I):

wherein: Z is tetrazole or CO₂Q; each Q is independently selected fromhydrogen or a protecting group; n is an integer selected from the groupconsisting of 1, 2, 3, and 4; R is H or C₁-C₄ alkyl; L is a linkergroup; and X is H or a photosensitizer moiety; or a pharmaceuticallyacceptable salt thereof.

In some embodiments, the linker group has the formula -L₁-L₂-L₃-,wherein each L₁, L₂, and L₃ can be present or absent and can be arrangedin any order, and wherein: L₁ is—NH—(CH₂)_(m)—[O—CH₂—CH₂—O]_(p)—(CH₂)_(q)—C(═O)—; L₂ is—NH—(CH₂)_(s)—C(COOH)—NH—; and L₃ is —(O═)C—(CH₂)_(t)—C(═O)—; wherein m,p, q, s, and t are each integers selected from the group consisting of1, 2, 3, 4, 5, and 6.

In some embodiments, the compound of formula (I) has the followingstereochemistry:

In particular embodiments, the compound of formula (I) is selected fromthe group consisting of:

In yet more particular embodiments, the photosensitizer moiety isselected from the group consisting of:

In some embodiments, the presently disclosed subject matter provides afluorescence imaging agent comprising a compound of formula (I).

i. Chemical Definitions

While the following terms in relation to compounds of formula (I) arebelieved to be well understood by one of ordinary skill in the art, thefollowing definitions are set forth to facilitate explanation of thepresently disclosed subject matter. These definitions are intended tosupplement and illustrate, not preclude, the definitions that would beapparent to one of ordinary skill in the art upon review of the presentdisclosure.

The terms substituted, whether preceded by the term “optionally” or not,and substituent, as used herein, refer to the ability, as appreciated byone skilled in this art, to change one functional group for anotherfunctional group provided that the valency of all atoms is maintained.When more than one position in any given structure may be substitutedwith more than one substituent selected from a specified group, thesubstituent may be either the same or different at every position. Thesubstituents also may be further substituted (e.g., an aryl groupsubstituent may have another substituent off it, such as another arylgroup, which is further substituted, for example, with fluorine at oneor more positions).

Where substituent groups or linking groups are specified by theirconventional chemical formulae, written from left to right, they equallyencompass the chemically identical substituents that would result fromwriting the structure from right to left, e.g., —CH₂O— is equivalent to—OCH₂—; —C(═O)O— is equivalent to —OC(═O)—; —OC(═O)NR— is equivalent to—NRC(═O)O—, and the like. As used herein, where an internal substituentis flanked by bonds (for example —NRC(O)—) the order of the atoms isfixed, the orientation of the group may not be reversed, and is insertedinto a structure in the orientation presented. In other words —NRC(O)—is not the same as —C(O)NR—. As used herein the term C(O) (for example—NRC(O)—) is used to indicate a carbonyl (C═O) group, where the oxygenis bonded to the carbon by a double bond.

When the term “independently selected” is used, the substituents beingreferred to (e.g., R groups, such as groups R₁, R₂, and the like, orvariables, such as “m” and “n”), can be identical or different. Forexample, both R₁ and R₂ can be substituted alkyls, or R₁ can be hydrogenand R₂ can be a substituted alkyl, and the like.

The terms “a,” “an,” or “a(n),” when used in reference to a group ofsubstituents herein, mean at least one. For example, where a compound issubstituted with “an” alkyl or aryl, the compound is optionallysubstituted with at least one alkyl and/or at least one aryl. Moreover,where a moiety is substituted with an R substituent, the group may bereferred to as “R-substituted.” Where a moiety is R-substituted, themoiety is substituted with at least one R substituent and each Rsubstituent is optionally different.

A named “R” or group will generally have the structure that isrecognized in the art as corresponding to a group having that name,unless specified otherwise herein. For the purposes of illustration,certain representative “R” groups as set forth above are defined below.

Descriptions of compounds of the present disclosure are limited byprinciples of chemical bonding known to those skilled in the art.Accordingly, where a group may be substituted by one or more of a numberof substituents, such substitutions are selected so as to comply withprinciples of chemical bonding and to give compounds which are notinherently unstable and/or would be known to one of ordinary skill inthe art as likely to be unstable under ambient conditions, such asaqueous, neutral, and several known physiological conditions. Forexample, a heterocycloalkyl or heteroaryl is attached to the remainderof the molecule via a ring heteroatom in compliance with principles ofchemical bonding known to those skilled in the art thereby avoidinginherently unstable compounds.

The term hydrocarbon, as used herein, refers to any chemical groupcomprising hydrogen and carbon. The hydrocarbon may be substituted orunsubstituted. As would be known to one skilled in this art, allvalencies must be satisfied in making any substitutions. The hydrocarbonmay be unsaturated, saturated, branched, unbranched, cyclic, polycyclic,or heterocyclic. Illustrative hydrocarbons are further defined hereinbelow and include, for example, methyl, ethyl, n-propyl, iso-propyl,cyclopropyl, allyl, vinyl, n-butyl, tert-butyl, ethynyl, cyclohexyl,methoxy, diethylamino, and the like.

The term “alkyl,” by itself or as part of another substituent, means,unless otherwise stated, a straight (i.e., unbranched) or branchedchain, acyclic or cyclic hydrocarbon group, or combination thereof,which may be fully saturated, mono- or polyunsaturated and can includedi- and multivalent groups, having the number of carbon atoms designated(i.e., C₁-C₁₀ means one to ten carbons). In particular embodiments, theterm “alkyl” refers to C₁₋₂₀ inclusive, linear (i.e., “straight-chain”),branched, or cyclic, saturated or at least partially and in some casesfully unsaturated (i.e., alkenyl and alkynyl) hydrocarbon radicalsderived from a hydrocarbon moiety containing between one and twentycarbon atoms by removal of a single hydrogen atom.

Representative saturated hydrocarbon groups include, but are not limitedto, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl,tert-butyl, n-pentyl, sec-pentyl, iso-pentyl, neopentyl, n-hexyl,sec-hexyl, n-heptyl, n-octyl, n-decyl, n-undecyl, dodecyl, cyclohexyl,(cyclohexyl)methyl, cyclopropylmethyl, and homologs and isomers thereof.

“Branched” refers to an alkyl group in which a lower alkyl group, suchas methyl, ethyl or propyl, is attached to a linear alkyl chain. “Loweralkyl” refers to an alkyl group having 1 to about 8 carbon atoms (i.e.,a C₁₋₈ alkyl), e.g., 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms. “Higheralkyl” refers to an alkyl group having about 10 to about 20 carbonatoms, e.g., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms.In certain embodiments, “alkyl” refers, in particular, to C₁₋₈straight-chain alkyls. In other embodiments, “alkyl” refers, inparticular, to C₁₋₈ branched-chain alkyls.

In certain embodiments, alkyl groups are C₁-C₆ alkyl groups or C₁-C₄alkyl groups. The term “C₁-C₆ alkyl” as used herein meansstraight-chain, branched, or cyclic C₁-C₆ hydrocarbons which arecompletely saturated and hybrids thereof, such as (cycloalkyl)alkyl.Examples of C₁-C₆ alkyl substituents include methyl (Me), ethyl (Et),propyl (including n-propyl (n-Pr, ^(n)Pr), iso-propyl (i-Pr, ¹Pr), andcyclopropyl (c-Pr, ⁰Pr)), butyl (including n-butyl (n-Bu, ^(n)Bu),iso-butyl (i-Bu, ¹Bu), sec-butyl (s-Bu, sBu), tert-butyl (t-Bu, ¹Bu), orcyclobutyl (c-Bu, ⁰Bu)), and so forth.

Alkyl groups can optionally be substituted (a “substituted alkyl”) withone or more alkyl group substituents, which can be the same ordifferent. The term “alkyl group substituent” includes but is notlimited to alkyl, substituted alkyl, halo, arylamino, acyl, hydroxyl,aryloxyl, alkoxyl, alkylthio, arylthio, aralkyloxyl, aralkylthio,carboxyl, alkoxycarbonyl, oxo, and cycloalkyl. There can be optionallyinserted along the alkyl chain one or more oxygen, sulfur or substitutedor unsubstituted nitrogen atoms, wherein the nitrogen substituent ishydrogen, lower alkyl (also referred to herein as “alkylaminoalkyl”), oraryl.

Thus, as used herein, the term “substituted alkyl” includes alkylgroups, as defined herein, in which one or more atoms or functionalgroups of the alkyl group are replaced with another atom or functionalgroup, including for example, alkyl, substituted alkyl, halogen, aryl,substituted aryl, alkoxyl, hydroxyl, nitro, amino, alkylamino,dialkylamino, sulfate, and mercapto.

The term “heteroalkyl,” by itself or in combination with another term,means, unless otherwise stated, a stable straight or branched chain, orcyclic hydrocarbon group, or combinations thereof, consisting of atleast one carbon atoms and at least one heteroatom selected from thegroup consisting of O, N, P, Si and S, and wherein the nitrogen,phosphorus, and sulfur atoms may optionally be oxidized and the nitrogenheteroatom may optionally be quaternized. The heteroatom(s) O, N, P andS and Si may be placed at any interior position of the heteroalkyl groupor at the position at which alkyl group is attached to the remainder ofthe molecule. Examples include, but are not limited to, —CH₂—CH₂—O—CH₃,—CH₂—CH₂—NH—CH₃, —CH₂—CH₂—N(CH₃)—CH₃, —CH₂—S—CH₂—CH₃,—CH₂—CH₂₅—S(O)—CH₃, —CH₂—CH₂—S(O)₂—CH₃, —CH═CH—O—CH₃, —Si(CH₃)₃,—CH₂—CH═N—OCH₃, —CH═CH—N(CH₃)—CH₃, O—CH₃, —O—CH₂—CH₃, and —CN. Up to twoor three heteroatoms may be consecutive, such as, for example,—CH₂—NH—OCH₃ and —CH₂—O—Si(CH₃)₃.

As described above, heteroalkyl groups, as used herein, include thosegroups that are attached to the remainder of the molecule through aheteroatom, such as —C(O)R′, —C(O)NR′, —NR′R″, —OR′, —SR, and/or —SO₂R′.Where “heteroalkyl” is recited, followed by recitations of specificheteroalkyl groups, such as —NR′R or the like, it will be understoodthat the terms heteroalkyl and —NR′R″ are not redundant or mutuallyexclusive. Rather, the specific heteroalkyl groups are recited to addclarity. Thus, the term “heteroalkyl” should not be interpreted hereinas excluding specific heteroalkyl groups, such as —NR′R″ or the like.

In the term “(cycloalkyl)alkyl”, cycloalkyl, and alkyl are as definedabove, and the point of attachment is on the alkyl group. This termencompasses, but is not limited to, cyclopropylmethyl,cyclopentylmethyl, and cyclohexylmethyl. The alkyl group may besubstituted or unsubstituted.

“Cyclic” and “cycloalkyl” refer to a non-aromatic mono- or multicyclicring system of about 3 to about 10 carbon atoms, e.g., 3, 4, 5, 6, 7, 8,9, or 10 carbon atoms. The cycloalkyl group can be optionally partiallyunsaturated. The cycloalkyl group also can be optionally substitutedwith an alkyl group substituent as defined herein, oxo, and/or alkylene.There can be optionally inserted along the cyclic alkyl chain one ormore oxygen, sulfur or substituted or unsubstituted nitrogen atoms,wherein the nitrogen substituent is hydrogen, alkyl, substituted alkyl,aryl, or substituted aryl, thus providing a heterocyclic group.Representative monocyclic cycloalkyl rings include cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

Multicyclic cycloalkyl rings include adamantyl, octahydronaphthyl,decalin, camphor, camphane, and noradamantyl, and fused ring systems,such as dihydro- and tetrahydronaphthalene, and the like.

The terms “cycloheteroalkyl” or “heterocycloalkyl” refer to anon-aromatic ring system, unsaturated or partially unsaturated ringsystem, such as a 3- to 10-member substituted or unsubstitutedcycloalkyl ring system, including one or more heteroatoms, which can bethe same or different, and are selected from the group consisting ofnitrogen (N), oxygen (O), sulfur (S), phosphorus (P), and silicon (Si),and optionally can include one or more double bonds.

The cycloheteroalkyl ring can be optionally fused to or otherwiseattached to other cycloheteroalkyl rings and/or non-aromatic hydrocarbonrings. Heterocyclic rings include those having from one to threeheteroatoms independently selected from oxygen, sulfur, and nitrogen, inwhich the nitrogen and sulfur heteroatoms may optionally be oxidized andthe nitrogen heteroatom may optionally be quaternized. In certainembodiments, the term heterocylic refers to a non-aromatic 5-, 6-, or7-membered ring or a polycyclic group wherein at least one ring atom isa heteroatom selected from O, S, and N (wherein the nitrogen and sulfurheteroatoms may be optionally oxidized), including, but not limited to,a bi- or tri-cyclic group, comprising fused six-membered rings havingbetween one and three heteroatoms independently selected from theoxygen, sulfur, and nitrogen, wherein (i) each 5-membered ring has 0 to2 double bonds, each 6-membered ring has 0 to 2 double bonds, and each7-membered ring has 0 to 3 double bonds, (ii) the nitrogen and sulfurheteroatoms may be optionally oxidized, (iii) the nitrogen heteroatommay optionally be quaternized, and (iv) any of the above heterocyclicrings may be fused to an aryl or heteroaryl ring. Representativecycloheteroalkyl ring systems include, but are not limited topyrrolidinyl, pyrrolinyl, imidazolidinyl, imidazolinyl, pyrazolidinyl,pyrazolinyl, piperidyl, piperazinyl, indolinyl, quinuclidinyl,morpholinyl, thiomorpholinyl, thiadiazinanyl, tetrahydrofuranyl, and thelike.

The terms “cycloalkyl” and “heterocycloalkyl”, by themselves or incombination with other terms, represent, unless otherwise stated, cyclicversions of “alkyl” and “heteroalkyl”, respectively. Additionally, forheterocycloalkyl, a heteroatom can occupy the position at which theheterocycle is attached to the remainder of the molecule. Examples ofcycloalkyl include, but are not limited to, cyclopentyl, cyclohexyl,1-cyclohexenyl, 3-cyclohexenyl, cycloheptyl, and the like. Examples ofheterocycloalkyl include, but are not limited to,1-(1,2,5,6-tetrahydropyridyl), 1-piperidinyl, 2-piperidinyl,3-piperidinyl, 4-morpholinyl, 3-morpholinyl, tetrahydrofuran-2-yl,tetrahydrofuran-3-yl, tetrahydrothien-2-yl, tetrahydrothien-3-yl,1-piperazinyl, 2-piperazinyl, and the like. The terms “cycloalkylene”and “heterocycloalkylene” refer to the divalent derivatives ofcycloalkyl and heterocycloalkyl, respectively.

The term “cycloalkylalkyl,” as used herein, refers to a cycloalkyl groupas defined hereinabove, which is attached to the parent molecular moietythrough an alkyl group, also as defined above. Examples ofcycloalkylalkyl groups include cyclopropylmethyl and cyclopentylethyl.

An unsaturated alkyl group is one having one or more double bonds ortriple bonds. Examples of unsaturated alkyl groups include, but are notlimited to, vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl),2,4-pentadienyl, 3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl,3-butynyl, and the higher homologs and isomers. Alkyl groups which arelimited to hydrocarbon groups are termed “homoalkyl.”

More particularly, the term “alkenyl” as used herein refers to amonovalent group derived from a C₁₋₂₀ inclusive straight or branchedhydrocarbon moiety having at least one carbon-carbon double bond by theremoval of a single hydrogen atom. Alkenyl groups include, for example,ethenyl (i.e., vinyl), propenyl, butenyl, 1-methyl-2-buten-1-yl,pentenyl, hexenyl, octenyl, and butadienyl.

The term “cycloalkenyl” as used herein refers to a cyclic hydrocarboncontaining at least one carbon-carbon double bond. Examples ofcycloalkenyl groups include cyclopropenyl, cyclobutenyl, cyclopentenyl,cyclopentadiene, cyclohexenyl, 1,3-cyclohexadiene, cycloheptenyl,cycloheptatrienyl, and cyclooctenyl.

The term “alkynyl” as used herein refers to a monovalent group derivedfrom a straight or branched C₁₋₂₀ hydrocarbon of a designed number ofcarbon atoms containing at least one carbon-carbon triple bond. Examplesof “alkynyl” include ethynyl, 2-propynyl (propargyl), 1-propynyl,pentynyl, hexynyl, heptynyl, and allenyl groups, and the like.

The term “alkylene” by itself or a part of another substituent refers toa straight or branched bivalent aliphatic hydrocarbon group derived froman alkyl group having from 1 to about 20 carbon atoms, e.g., 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbonatoms. The alkylene group can be straight, branched or cyclic. Thealkylene group also can be optionally unsaturated and/or substitutedwith one or more “alkyl group substituents.” There can be optionallyinserted along the alkylene group one or more oxygen, sulfur orsubstituted or unsubstituted nitrogen atoms (also referred to herein as“alkylaminoalkyl”), wherein the nitrogen substituent is alkyl aspreviously described. Exemplary alkylene groups include methylene(—CH₂—); ethylene (—CH₂—CH₂—); propylene (—(CH₂)₃—); cyclohexylene(—C₆H₁₀—); —CH═CH—CH═CH—; —CH═CH—CH₂—; —CH₂CH₂CH₂CH₂—, —CH₂CH═CHCH₂—,—CH₂CsCCH₂—, —CH₂CH₂CH(CH₂CH₂CH₃)CH₂—, —(CH₂)_(q)—N(R)—(CH₂)_(r)—,wherein each of q and r is independently an integer from 0 to about 20,e.g., 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, or 20, and R is hydrogen or lower alkyl; methylenedioxyl(—O—CH₂—O—); and ethylenedioxyl (—O—(CH₂)₂—O—). An alkylene group canhave about 2 to about 3 carbon atoms and can further have 6-20 carbons.Typically, an alkyl (or alkylene) group will have from 1 to 24 carbonatoms, with those groups having 10 or fewer carbon atoms being someembodiments of the present disclosure. A “lower alkyl” or “loweralkylene” is a shorter chain alkyl or alkylene group, generally havingeight or fewer carbon atoms.

The term “heteroalkylene” by itself or as part of another substituentmeans a divalent group derived from heteroalkyl, as exemplified, but notlimited by, —CH₂—CH₂—S—CH₂—CH₂— and —CH₂—S—CH₂—CH₂—NH—CH₂—. Forheteroalkylene groups, heteroatoms can also occupy either or both of thechain termini (e.g., alkyleneoxo, alkylenedioxo, alkyleneamino,alkylenediamino, and the like). Still further, for alkylene andheteroalkylene linking groups, no orientation of the linking group isimplied by the direction in which the formula of the linking group iswritten. For example, the formula —C(O)OR′— represents both —C(O)OR′—and —R′OC(O)—.

The term “aryl” means, unless otherwise stated, an aromatic hydrocarbonsubstituent that can be a single ring or multiple rings (such as from 1to 3 rings), which are fused together or linked covalently.

The term “heteroaryl” refers to aryl groups (or rings) that contain fromone to four heteroatoms (in each separate ring in the case of multiplerings) selected from N, O, and S, wherein the nitrogen and sulfur atomsare optionally oxidized, and the nitrogen atom(s) are optionallyquaternized. A heteroaryl group can be attached to the remainder of themolecule through a carbon or heteroatom. Non-limiting examples of aryland heteroaryl groups include phenyl, 1-naphthyl, 2-naphthyl,4-biphenyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 3-pyrazolyl,2-imidazolyl, 4-imidazolyl, pyrazinyl, 2-oxazolyl, 4-oxazolyl,2-phenyl-4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl,5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 2-furyl, 3-furyl,2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl,4-pyrimidyl, 5-benzothiazolyl, purinyl, 2-benzimidazolyl, 5-indolyl,indazolyl, 1-isoquinolyl, 5-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl,3-quinolyl, and 6-quinolyl. Substituents for each of above noted aryland heteroaryl ring systems are selected from the group of acceptablesubstituents described below. The terms “arylene” and “heteroarylene”refer to the divalent forms of aryl and heteroaryl, respectively.

For brevity, the term “aryl” when used in combination with other terms(e.g., aryloxo, arylthioxo, arylalkyl) includes both aryl and heteroarylrings as defined above. Thus, the terms “arylalkyl” and“heteroarylalkyl” are meant to include those groups in which an aryl orheteroaryl group is attached to an alkyl group (e.g., benzyl, phenethyl,pyridylmethyl, furylmethyl, and the like) including those alkyl groupsin which a carbon atom (e.g., a methylene group) has been replaced by,for example, an oxygen atom (e.g., phenoxymethyl, 2-pyridyloxymethyl,3-(l-naphthyloxy)propyl, and the like). The term “haloaryl,” however, asused herein, is meant to cover only aryls substituted with one or morehalogens.

Where a heteroalkyl, heterocycloalkyl, or heteroaryl includes a specificnumber of members (e.g. “3 to 7 membered”), the term “member” refers toa carbon or heteroatom.

As used herein, the term “alkylaryl” includes alkyl groups, as definedabove, substituted by aryl groups, as defined above. The aryl group maybe connected at any point on the alkyl group. The term C₄-C₁₆ alkylarylincludes alkylaryl groups having a total of 4 to 16 carbon atoms,counting the carbon atoms on the alkyl group and aryl group together.Examples of alkylaryl groups include but are not limited to benzyl(phenylmethyl), phenyl ethyl, and naphthylmethyl. The alkylaryl groupmay be substituted or unsubstituted. Substituents are not countedtowards the total number of atoms in the alkylaryl group, so long as thetotal atoms in the substituent(s) are not larger than the alkylarylgroup.

Further, a structure represented generally by the formula:

as used herein refers to a ring structure, for example, but not limitedto a 3-carbon, a 4-carbon, a 5-carbon, a 6-carbon, a 7-carbon, and thelike, aliphatic and/or aromatic cyclic compound, including a saturatedring structure, a partially saturated ring structure, and an unsaturatedring structure, comprising a substituent R group, wherein the R groupcan be present or absent, and when present, one or more R groups caneach be substituted on one or more available carbon atoms of the ringstructure. The presence or absence of the R group and number of R groupsis determined by the value of the variable “n,” which is an integergenerally having a value ranging from 0 to the number of carbon atoms onthe ring available for substitution. Each R group, if more than one, issubstituted on an available carbon of the ring structure rather than onanother R group. For example, the structure above where n is 0 to 2would comprise compound groups including, but not limited to:

and the like.

A dashed line representing a bond in a cyclic ring structure indicatesthat the bond can be either present or absent in the ring. That is, adashed line representing a bond in a cyclic ring structure indicatesthat the ring structure is selected from the group consisting of asaturated ring structure, a partially saturated ring structure, and anunsaturated ring structure.

A substituent bearing a broken bond, such as the example shown below,means that the substituent is directly bonded to the molecule at theindicated position. No additional methylene (CH₂) groups are implied.The symbol (

) denotes the point of attachment of a moiety to the remainder of themolecule.

Substituents bearing two broken bonds, such as the example shown below,means that the orientation of the atoms is as-indicated, left to rightand should be inserted into a molecule in the orientation shown. Noadditional methylene (CH₂) groups are implied unless specificallyindicated.

When a named atom of an aromatic ring or a heterocyclic aromatic ring isdefined as being “absent,” the named atom is replaced by a direct bond.

Each of above terms (e.g., “alkyl,” “heteroalkyl,” “cycloalkyl, and“heterocycloalkyl”, “aryl,” “heteroaryl,” “phosphonate,” and “sulfonate”as well as their divalent derivatives) are meant to include bothsubstituted and unsubstituted forms of the indicated group. Optionalsubstituents for each type of group are provided below.

Substituents for alkyl, heteroalkyl, cycloalkyl, heterocycloalkylmonovalent and divalent derivative groups (including those groups oftenreferred to as alkylene, alkenyl, heteroalkylene, heteroalkenyl,alkynyl, cycloalkyl, heterocycloalkyl, cycloalkenyl, andheterocycloalkenyl) can be one or more of a variety of groups selectedfrom, but not limited to: —OR′, ═O, ═NR′, ═N—OR′, —NR′R″, —SR′,-halogen, —SiR′R″R′″, —OC(O)R′, —C(O)R′, —CO₂R′, —C(O)NR′R″,—OC(O)NR′R″, —NR″C(O)R′, —NR′ —C(O)NR″R′″, —NR″C(O)OR′,—NR—C(NR′R″)═NR′″, —S(O)R′, —S(O)₂R′, —S(O)₂NR′R″, —NRSO₂R′, —CN and—NO₂ in a number ranging from zero to (2m′+1), where m′ is the totalnumber of carbon atoms in such groups. R′, R″, R′″ and R″″ each mayindependently refer to hydrogen, substituted or unsubstitutedheteroalkyl, substituted or unsubstituted cycloalkyl, substituted orunsubstituted heterocycloalkyl, substituted or unsubstituted aryl (e.g.,aryl substituted with 1-3 halogens), substituted or unsubstituted alkyl,alkoxy or thioalkoxy groups, or arylalkyl groups. As used herein, an“alkoxy” group is an alkyl attached to the remainder of the moleculethrough a divalent oxygen. When a compound of the disclosure includesmore than one R group, for example, each of the R groups isindependently selected as are each R′, R″, R′″ and R″″ groups when morethan one of these groups is present. When R′ and R″ are attached to thesame nitrogen atom, they can be combined with the nitrogen atom to forma 4-, 5-, 6-, or 7-membered ring. For example, —NR′R″ is meant toinclude, but not be limited to, 1-pyrrolidinyl and 4-morpholinyl. Fromthe above discussion of substituents, one of skill in the art willunderstand that the term “alkyl” is meant to include groups includingcarbon atoms bound to groups other than hydrogen groups, such ashaloalkyl (e.g., —CF₃ and —CH₂CF₃) and acyl (e.g., —C(O)CH₃, —C(O)CF₃,—C(O)CH₂OCH₃, and the like).

Similar to the substituents described for alkyl groups above, exemplarysubstituents for aryl and heteroaryl groups (as well as their divalentderivatives) are varied and are selected from, for example: halogen,—OR′, —NR′R″, —SR′, -halogen, —SiR′R″R′″, —OC(O)R′, —C(O)R′, —CO₂R′,—C(O)NR′R″, —OC(O)NR′R″, —NR″C(O)R′, —NR′ —C(O)NR″R′″, —NR″C(O)OR′,—NR—C(NR′R″R′″)═NR″″, —NR—C(NR′R″) ═NR′″ —S(O)R′, —S(O)₂R′, —S(O)₂NR′R″,—NRSO₂R′, —CN and —NO₂, —R′, —N₃, —CH(Ph)₂, fluoro(C₁-C₄)alkoxo, andfluoro(C₁-C₄)alkyl, in a number ranging from zero to the total number ofopen valences on aromatic ring system; and where R′, R″, R′″ and R″″ maybe independently selected from hydrogen, substituted or unsubstitutedalkyl, substituted or unsubstituted heteroalkyl, substituted orunsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl,substituted or unsubstituted aryl and substituted or unsubstitutedheteroaryl. When a compound of the disclosure includes more than one Rgroup, for example, each of the R groups is independently selected asare each R′, R″, R′″ and R″″ groups when more than one of these groupsis present.

Two of the substituents on adjacent atoms of aryl or heteroaryl ring mayoptionally form a ring of the formula —T-C(O)—(CRR′)_(q)—U—, wherein Tand U are independently —NR—, —O—, —CRR′— or a single bond, and q is aninteger of from 0 to 3. Alternatively, two of the substituents onadjacent atoms of aryl or heteroaryl ring may optionally be replacedwith a substituent of the formula —A-(CH₂)_(r)—B—, wherein A and B areindependently —CRR′—, —O—, —NR—, —S—, —S(O)—, —S(O)₂—, —S(O)₂NR′— or asingle bond, and r is an integer of from 1 to 4.

One of the single bonds of the new ring so formed may optionally bereplaced with a double bond. Alternatively, two of the substituents onadjacent atoms of aryl or heteroaryl ring may optionally be replacedwith a substituent of the formula —(CRR′)_(s)—X′—(C″R′″)_(d)—, where sand d are independently integers of from 0 to 3, and X′ is —O—, —NR′—,—S—, —S(O)—, —S(O)₂—, or —S(O)₂NR′ —. The substituents R, R′, R″ and R′″may be independently selected from hydrogen, substituted orunsubstituted alkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, and substituted or unsubstituted heteroaryl.

As used herein, the term “acyl” refers to an organic acid group whereinthe —OH of the carboxyl group has been replaced with another substituentand has the general formula RC(═O)—, wherein R is an alkyl, alkenyl,alkynyl, aryl, carbocylic, heterocyclic, or aromatic heterocyclic groupas defined herein). As such, the term “acyl” specifically includesarylacyl groups, such as an acetylfuran and a phenacyl group. Specificexamples of acyl groups include acetyl and benzoyl.

The terms “alkoxyl” or “alkoxy” are used interchangeably herein andrefer to a saturated (i.e., alkyl-O—) or unsaturated (i.e., alkenyl-O—and alkynyl-O—) group attached to the parent molecular moiety through anoxygen atom, wherein the terms “alkyl,” “alkenyl,” and “alkynyl” are aspreviously described and can include C₁₋₂₀ inclusive, linear, branched,or cyclic, saturated or unsaturated oxo-hydrocarbon chains, including,for example, methoxyl, ethoxyl, propoxyl, isopropoxyl, n-butoxyl,sec-butoxyl, t-butoxyl, and n-pentoxyl, neopentoxyl, n-hexoxyl, and thelike.

The term “alkoxyalkyl” as used herein refers to an alkyl-O-alkyl ether,for example, a methoxyethyl or an ethoxymethyl group.

“Aryloxyl” refers to an aryl-O— group wherein the aryl group is aspreviously described, including a substituted aryl. The term “aryloxyl”as used herein can refer to phenyloxyl or hexyloxyl, and alkyl,substituted alkyl, halo, or alkoxyl substituted phenyloxyl or hexyloxyl.

“Aralkyl” refers to an aryl-alkyl-group wherein aryl and alkyl are aspreviously described, and included substituted aryl and substitutedalkyl. Exemplary aralkyl groups include benzyl, phenylethyl, andnaphthylmethyl.

“Aralkyloxyl” refers to an aralkyl-O— group wherein the aralkyl group isas previously described. An exemplary aralkyloxyl group is benzyloxyl.

“Alkoxycarbonyl” refers to an alkyl-O—CO— group. Exemplaryalkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl,butyloxycarbonyl, and t-butyloxycarbonyl.

“Aryloxycarbonyl” refers to an aryl-O—CO— group. Exemplaryaryloxycarbonyl groups include phenoxy- and naphthoxy-carbonyl.

“Aralkoxycarbonyl” refers to an aralkyl-O—CO— group. An exemplaryaralkoxycarbonyl group is benzyloxycarbonyl.

“Carbamoyl” refers to an amide group of the formula —CONH₂.“Alkylcarbamoyl” refers to a R′RN—CO— group wherein one of R and R′ ishydrogen and the other of R and R′ is alkyl and/or substituted alkyl aspreviously described. “Dialkylcarbamoyl” refers to a R′RN—CO— groupwherein each of R and R′ is independently alkyl and/or substituted alkylas previously described.

The term carbonyldioxyl, as used herein, refers to a carbonate group ofthe formula —O—CO—OR.

“Acyloxyl” refers to an acyl-O— group wherein acyl is as previouslydescribed.

The term “amino” refers to the —NH₂ group and also refers to a nitrogencontaining group as is known in the art derived from ammonia by thereplacement of one or more hydrogen radicals by organic radicals. Forexample, the terms “acylamino” and “alkylamino” refer to specificN-substituted organic radicals with acyl and alkyl substituent groupsrespectively.

An “aminoalkyl” as used herein refers to an amino group covalently boundto an alkylene linker. More particularly, the terms alkylamino,dialkylamino, and trialkylamino as used herein refer to one, two, orthree, respectively, alkyl groups, as previously defined, attached tothe parent molecular moiety through a nitrogen atom. The term alkylaminorefers to a group having the structure —NHR′ wherein R′ is an alkylgroup, as previously defined; whereas the term dialkylamino refers to agroup having the structure —NR′R″, wherein R′ and R″ are eachindependently selected from the group consisting of alkyl groups. Theterm trialkylamino refers to a group having the structure —NR′R″R′″,wherein R′, R″, and R′″ are each independently selected from the groupconsisting of alkyl groups. Additionally, R′, R″, and/or R′″ takentogether may optionally be —(CH₂)_(k)— where k is an integer from 2 to6. Examples include, but are not limited to, methylamino, dimethylamino,ethylamino, diethylamino, diethylaminocarbonyl, methylethylamino,iso-propylamino, piperidino, trimethylamino, and propylamino.

The amino group is —NR′R″, wherein R′ and R″ are typically selected fromhydrogen, substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl.

The terms alkylthioether and thioalkoxyl refer to a saturated (i.e.,alkyl-S—) or unsaturated (i.e., alkenyl-S— and alkynyl-S—) groupattached to the parent molecular moiety through a sulfur atom. Examplesof thioalkoxyl moieties include, but are not limited to, methylthio,ethylthio, propylthio, isopropylthio, n-butylthio, and the like.

“Acylamino” refers to an acyl-NH— group wherein acyl is as previouslydescribed. “Aroylamino” refers to an aroyl-NH— group wherein aroyl is aspreviously described.

The term “carbonyl” refers to the —(C═O)— group.

The term “carboxyl” refers to the —COOH group. Such groups also arereferred to herein as a “carboxylic acid” moiety.

The terms “halo,” “halide,” or “halogen” as used herein refer to fluoro,chloro, bromo, and iodo groups. Additionally, terms such as “haloalkyl,”are meant to include monohaloalkyl and polyhaloalkyl. For example, theterm “halo(C₁-C₄)alkyl” is mean to include, but not be limited to,trifluoromethyl, 2,2,2-trifluoroethyl, 4-chlorobutyl, 3-bromopropyl, andthe like.

The term “hydroxyl” refers to the —OH group.

The term “hydroxyalkyl” refers to an alkyl group substituted with an —OHgroup.

The term “mercapto” refers to the —SH group.

The term “oxo” as used herein means an oxygen atom that is double bondedto a carbon atom or to another element.

The term “nitro” refers to the —NO₂ group.

The term “thio” refers to a compound described previously herein whereina carbon or oxygen atom is replaced by a sulfur atom.

The term “sulfate” refers to the —SO₄ group.

The term thiohydroxyl or thiol, as used herein, refers to a group of theformula —SH.

The term ureido refers to a urea group of the formula —NH—CO—NH₂.

Unless otherwise explicitly defined, a “substituent group,” as usedherein, includes a functional group selected from one or more of thefollowing moieties, which are defined herein:

(A) —OH, —NH₂, —SH, —CN, —CF₃, —NO₂, Oxo, halogen, unsubstituted alkyl,unsubstituted heteroalkyl, unsubstituted cycloalkyl, unsubstitutedheterocycloalkyl, unsubstituted aryl, unsubstituted heteroaryl, and

(B) alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, andheteroaryl, substituted with at least one substituent selected from:

(i) oxo, —OH, —NH₂, —SH, —CN, —CF₃, —NO₂, halogen, unsubstituted alkyl,unsubstituted heteroalkyl, unsubstituted cycloalkyl, unsubstitutedheterocycloalkyl, unsubstituted aryl, unsubstituted heteroaryl, and

(ii) alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, andheteroaryl, substituted with at least one substituent selected from:

(a) oxo, —OH, —NH₂, —SH, —CN, —CF₃, —NO₂, halogen, unsubstituted alkyl,unsubstituted heteroalkyl, unsubstituted cycloalkyl, unsubstitutedheterocycloalkyl, unsubstituted aryl, unsubstituted heteroaryl, and

(b) alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, orheteroaryl, substituted with at least one substituent selected from oxo,—OH, —NH₂, —SH, —CN, —CF₃, —NO₂, halogen, unsubstituted alkyl,unsubstituted heteroalkyl, unsubstituted cycloalkyl, unsubstitutedheterocycloalkyl, unsubstituted aryl, and unsubstituted heteroaryl.

A “lower substituent” or “lower substituent group,” as used herein meansa group selected from all of the substituents described hereinabove fora “substituent group,” wherein each substituted or unsubstituted alkylis a substituted or unsubstituted C₁-C₈ alkyl, each substituted orunsubstituted heteroalkyl is a substituted or unsubstituted 2 to 8membered heteroalkyl, each substituted or unsubstituted cycloalkyl is asubstituted or unsubstituted C₅-C₇ cycloalkyl, and each substituted orunsubstituted heterocycloalkyl is a substituted or unsubstituted 5 to 7membered heterocycloalkyl.

A “size-limited substituent” or “size-limited substituent group,” asused herein means a group selected from all of the substituentsdescribed above for a “substituent group,” wherein each substituted orunsubstituted alkyl is a substituted or unsubstituted C₁-C₂₀ alkyl, eachsubstituted or unsubstituted heteroalkyl is a substituted orunsubstituted 2 to 20 membered heteroalkyl, each substituted orunsubstituted cycloalkyl is a substituted or unsubstituted C₄-C₈cycloalkyl, and each substituted or unsubstituted heterocycloalkyl is asubstituted or unsubstituted 4 to 8 membered heterocycloalkyl.

Throughout the specification and claims, a given chemical formula orname shall encompass all tautomers, congeners, and optical- andstereoisomers, as well as racemic mixtures where such isomers andmixtures exist.

It will be apparent to one skilled in the art that certain compounds ofthis disclosure may exist in tautomeric forms, all such tautomeric formsof the compounds being within the scope of the disclosure. The term“tautomer,” as used herein, refers to one of two or more structuralisomers which exist in equilibrium and which are readily converted fromone isomeric form to another.

Unless otherwise stated, structures depicted herein are also meant toinclude all stereochemical forms of the structure; i.e., the R and Sconfigurations for each asymmetric center. Therefore, singlestereochemical isomers as well as enantiomeric and diastereomericmixtures of the present compounds are within the scope of thedisclosure.

Certain compounds of the present disclosure possess asymmetric carbonatoms (optical or chiral centers) or double bonds; the enantiomers,racemates, diastereomers, tautomers, geometric isomers, stereoisometricforms that may be defined, in terms of absolute stereochemistry, as (R)-or (S)- or, as (D)- or (L)- for amino acids, and individual isomers areencompassed within the scope of the present disclosure. The compounds ofthe present disclosure do not include those which are known in art to betoo unstable to synthesize and/or isolate. The present disclosure ismeant to include compounds in racemic and optically pure forms.Optically active (R)- and (S)-, or (D)- and (L)-isomers may be preparedusing chiral synthons or chiral reagents, or resolved using conventionaltechniques. When the compounds described herein contain olefenic bondsor other centers of geometric asymmetry, and unless specified otherwise,it is intended that the compounds include both E and Z geometricisomers.

It is well known in the art how to prepare optically active forms, suchas by resolution of racemic forms (racemates), by asymmetric synthesis,or by synthesis from optically active starting materials. Resolution ofthe racemates can be accomplished, for example, by conventional methodssuch as crystallization in the presence of a resolving agent, orchromatography, using, for example a chiral HPLC column. Many geometricisomers of olefins, C═N double bonds, and the like also can be presentin the compounds described herein, and all such stable isomers arecontemplated in the presently disclosed subject matter. Cis and transgeometric isomers of the compounds of the presently disclosed subjectmatter are described and may be isolated as a mixture of isomers or asseparated isomeric forms. All chiral (enantiomeric and diastereomeric),and racemic forms, as well as all geometric isomeric forms of astructure are intended, unless the specific stereochemistry or isomericform is specifically indicated.

The compounds herein described may have one or more charged atoms. Forexample, the compounds may be zwitterionic, but may be neutral overall.Other embodiments may have one or more charged groups, depending on thepH and other factors. In these embodiments, the compound may beassociated with a suitable counter-ion. It is well known in the art howto prepare salts or exchange counter-ions. Generally, such salts can beprepared by reacting free acid forms of these compounds with astoichiometric amount of the appropriate base (such as Na, Ca, Mg, or Khydroxide, carbonate, bicarbonate, or the like), or by reacting freebase forms of these compounds with a stoichiometric amount of theappropriate acid. Such reactions are typically carried out in water orin an organic solvent, or in a mixture of the two. Counter-ions may bechanged, for example, by ion-exchange techniques such as ion-exchangechromatography. All zwitterions, salts and counter-ions are intended,unless the counter-ion or salt is specifically indicated. In certainembodiments, the salt or counter-ion may be pharmaceutically acceptable,for administration to a subject. Pharmaceutically acceptable salts arediscussed later.

As used herein, a “protecting group” is a chemical substituent which canbe selectively removed by readily available reagents which do not attackthe regenerated functional group or other functional groups in themolecule. Suitable protecting groups are known in the art and continueto be developed. Suitable protecting groups may be found, for example inWutz et al. (“Greene's Protective Groups in Organic Synthesis, FourthEdition,” Wiley-Interscience, 2007). Protecting groups for protection ofthe carboxyl group, as described by Wutz et al. (pages 533-643), areused in certain embodiments. In some embodiments, the protecting groupis removable by treatment with acid. Specific examples of protectinggroups include but are not limited to, benzyl, p-methoxybenzyl (PMB),tertiary butyl (¹Bu), methoxymethyl (MOM), methoxyethoxymethyl (MEM),methylthiomethyl (MTM), tetrahydropyranyl (THP), tetrahydrofuranyl(THF), benzyloxymethyl (BOM), trimethylsilyl (TMS), triethylsilyl (TES),t-butyldimethylsilyl (TBDMS), and triphenylmethyl (trityl, Tr). Personsskilled in the art will recognize appropriate situations in whichprotecting groups are required and will be able to select an appropriateprotecting group for use in a particular circumstance.

Unless otherwise stated, structures depicted herein are also meant toinclude compounds which differ only in the presence of one or moreisotopically enriched atoms. For example, compounds having the presentstructures except for the replacement of a hydrogen by a deuterium ortritium, or the replacement of a carbon by ¹³C- or ¹⁴C-enriched carbonare within the scope of this disclosure.

The compounds of the present disclosure may also contain unnaturalproportions of atomic isotopes at one or more of atoms that constitutesuch compounds. For example, the compounds may be radiolabeled withradioactive isotopes, such as for example tritium (³H), iodine-125 (¹²⁵I) or carbon-14 (¹⁴C). All isotopic variations of the compounds of thepresent disclosure, whether radioactive or not, are encompassed withinthe scope of the present disclosure.

ii. Pharmaceutical Salts

The compounds of the present disclosure may exist as pharmaceuticallyacceptable salts. The term “pharmaceutically acceptable salts” is meantto include salts of active compounds which are prepared with relativelynontoxic acids or bases, depending on the particular substituentmoieties found on the compounds described herein. Pharmaceuticallyacceptable salts are generally well known to those of ordinary skill inthe art, and may include, by way of example but not limitation, acetate,benzenesulfonate, besylate, benzoate, bicarbonate, bitartrate, bromide,calcium edetate, carnsylate, carbonate, citrate, edetate, edisylate,estolate, esylate, fumarate, gluceptate, gluconate, glutamate,glycollylarsanilate, hexylresorcinate, hydrabamine, hydrobromide,hydrochloride, hydroxynaphthoate, iodide, isethionate, lactate,lactobionate, malate, maleate, mandelate, mesylate, mucate, napsylate,nitrate, pamoate (embonate), pantothenate, phosphate/diphosphate,polygalacturonate, salicylate, stearate, subacetate, succinate, sulfate,tannate, tartrates, (e.g. (+)-tartrates, (−)-tartrates or mixturesthereof including racemic mixtures), or teoclate. These salts may beprepared by methods known to those skilled in art. Otherpharmaceutically acceptable salts may be found in, for example,Remington: The Science and Practice of Pharmacy (20^(th) ed.)Lippincott, Williams & Wilkins (2000).

Also included are base addition salts such as sodium, potassium,calcium, ammonium, organic amino, or magnesium salt, or a similar salt.When compounds of the present disclosure contain relatively basicfunctionalities, acid addition salts can be obtained by contacting theneutral form of such compounds with a sufficient amount of the desiredacid, either neat or in a suitable inert solvent. Examples of acceptableacid addition salts include those derived from inorganic acids likehydrochloric, hydrobromic, nitric, carbonic, monohydrogencarbonic,phosphoric, monohydrogenphosphoric, dihydrogenphosphoric, sulfuric,monohydrogensulfuric, hydriodic, or phosphorous acids and the like, aswell as the salts derived organic acids like acetic, propionic,isobutyric, maleic, malonic, benzoic, succinic, suberic, fumaric,lactic, mandelic, phthalic, benzenesulfonic, p-tolylsulfonic, citric,tartaric, methanesulfonic, and the like.

Also included are salts of amino acids such as arginate and the like,and salts of organic acids like glucuronic or galactunoric acids and thelike, see, for example, Berge et al, “Pharmaceutical Salts”, Journal ofPharmaceutical Science, 1977, 66, 1-19). Certain specific compounds ofthe present disclosure contain both basic and acidic functionalitiesthat allow the compounds to be converted into either base or acidaddition salts. The neutral forms of the compounds may be regenerated bycontacting the salt with a base or acid and isolating the parentcompound in the conventional manner. The parent form of the compounddiffers from the various salt forms in certain physical properties, suchas solubility in polar solvents.

Certain compounds of the present disclosure can exist in unsolvatedforms as well as solvated forms, including hydrated forms. In general,the solvated forms are equivalent to unsolvated forms and areencompassed within the scope of the present disclosure. Certaincompounds of the present disclosure may exist in multiple crystalline oramorphous forms. In general, all physical forms are equivalent for theuses contemplated by the present disclosure and are intended to bewithin the scope of the present disclosure.

In addition to salt forms, the present disclosure provides compounds,which are in a prodrug form. Prodrugs of the compounds described hereinare those compounds that readily undergo chemical changes underphysiological conditions to provide the compounds of the presentdisclosure. Additionally, prodrugs can be converted to the compounds ofthe present disclosure by chemical or biochemical methods in an ex vivoenvironment. For example, prodrugs can be slowly converted to thecompounds of the present disclosure when placed in a transdermal patchreservoir with a suitable enzyme or chemical reagent.

iii. Pharmaceutical Compositions and Kits

The compounds disclosed herein can be formulated into variouscompositions, for use in diagnostic, imaging or therapeutic treatmentmethods. The compositions (e.g. pharmaceutical compositions) can beassembled as a kit. Generally, a pharmaceutical composition comprises aneffective amount (e.g., a pharmaceutically effective amount, ordetectably effective amount) of a compound described above.

A presently disclosed composition can be formulated as a pharmaceuticalcomposition, which comprises a presently disclosed compound andpharmaceutically acceptable carrier. By a “pharmaceutically acceptablecarrier” is meant a material that is not biologically or otherwiseundesirable, i.e., the material may be administered to a subject withoutcausing any undesirable biological effects or interacting in adeleterious manner with any of the other components of thepharmaceutical composition in which it is contained. The carrier wouldnaturally be selected to minimize any degradation of the activeingredient and to minimize any adverse side effects in the subject, aswould be well known to one of skill in the art. For a discussion ofpharmaceutically acceptable carriers and other components ofpharmaceutical compositions, see, e.g., Remington's PharmaceuticalSciences, 18¹ ed., Mack Publishing Company, 1990. Some suitablepharmaceutical carriers will be evident to a skilled worker and include,e.g., water (including sterile and/or deionized water), suitable buffers(such as PBS), physiological saline, cell culture medium (such as DMEM),artificial cerebral spinal fluid, or the like.

A pharmaceutical composition or kit of the presently disclosed subjectmatter can contain other pharmaceuticals, in addition to the compound.The other agent(s) can be administered at any suitable time during thetreatment of the patient, either concurrently or sequentially.

One skilled in the art will appreciate that the particular formulationwill depend, in part, upon the particular agent that is employed, andthe chosen route of administration. Accordingly, there is a wide varietyof suitable formulations of compositions of the presently disclosedsubject matter.

One skilled in the art will appreciate that a suitable or appropriateformulation can be selected, adapted or developed based upon theparticular application at hand. Dosages for presently disclosedcompositions can be in unit dosage form. The term “unit dosage form” asused herein refers to physically discrete units suitable as unitarydosages for animal (e.g. human) subjects, each unit containing apredetermined quantity of a presently disclosed agent, alone or incombination with other therapeutic agents, calculated in an amountsufficient to produce the desired effect in association with apharmaceutically acceptable diluent, carrier, or vehicle.

One skilled in the art can easily determine the appropriate dose,schedule, and method of administration for the exact formulation of thecomposition being used, in order to achieve the desired effective amountor effective concentration of the agent in the individual patient.

The dose of a presently disclosed composition, administered to ananimal, particularly a human, in the context of the presently disclosedsubject matter should be sufficient to produce at least a detectableamount of a diagnostic or therapeutic response in the individual over areasonable time frame. The dose used to achieve a desired effect will bedetermined by a variety of factors, including the potency of theparticular agent being administered, the pharmacodynamics associatedwith the agent in the host, the severity of the disease state ofinfected individuals, other medications being administered to thesubject, and the like. The size of the dose also will be determined bythe existence of any adverse side effects that may accompany theparticular agent, or composition thereof, employed. It is generallydesirable, whenever possible, to keep adverse side effects to a minimum.The dose of the biologically active material will vary; suitable amountsfor each particular agent will be evident to a skilled worker.

Other embodiments provide kits including a compound according to thepresently disclosed subject matter. In certain embodiments, the kitprovides packaged pharmaceutical compositions having a pharmaceuticallyacceptable carrier and a compound of the presently disclosed subjectmatter. In some embodiments the packaged pharmaceutical composition willinclude the reaction precursors necessary to generate the compound ofthe presently disclosed subject matter upon combination with aradionuclide. Other packaged pharmaceutical compositions provided by thepresently disclosed subject matter further comprise indicia comprisingat least one of: instructions for preparing compounds according to thepresently disclosed subject matter from supplied precursors,instructions for using the composition to image cells or tissuesexpressing PSMA, or instructions for using the composition to imageglutamatergic neurotransmission in a patient suffering from astress-related disorder, or instructions for using the composition toimage prostate cancer.

In certain embodiments, a kit according to the presently disclosedsubject matter contains an agent described above in combination with apharmaceutically acceptable carrier. The agent and carrier may beprovided in solution or in lyophilized form. When the agent and carrierof the kit are in lyophilized form, the kit may optionally contain asterile and physiologically acceptable reconstitution medium such aswater, saline, buffered saline, and the like. The kit may provide acompound of the presently disclosed subject matter in solution or inlyophilized form, and these components of the kit of the presentlydisclosed subject matter may optionally contain stabilizers such asNaCl, silicate, phosphate buffers, ascorbic acid, gentisic acid, and thelike. Additional stabilization of kit components may be provided in thisembodiment, for example, by providing the reducing agent in anoxidation-resistant form.

Determination and optimization of such stabilizers and stabilizationmethods are well within the level of skill in the art.

A “pharmaceutically acceptable carrier” refers to a biocompatiblesolution, having due regard to sterility, p[Eta], isotonicity,stability, and the like and can include any and all solvents, diluents(including sterile saline, Sodium Chloride Injection, Ringer'sInjection, Dextrose Injection, Dextrose and Sodium Chloride Injection,Lactated Ringer's Injection and other aqueous buffer solutions),dispersion media, coatings, antibacterial and antifungal agents,isotonic agents, and the like. The pharmaceutically acceptable carrieralso can contain stabilizers, preservatives, antioxidants, or otheradditives, which are well known to one of skill in the art, or othervehicles as known in the art.

B. Methods of Treatment

The presently disclosed PSMA-targeted PDT agents have been shown toconcentrate selectively within PSMA-expressing tumors, therefore theywill enhance the specificity and efficiency of PDT. The presentlydisclosed PSMA-targeted photosensitizers also can serve as fluorescenceimaging agents to monitor target uptake and response to therapy.

Embodiments of the presently disclosed subject matter include methodsfor treating a tumor, the method comprising administering atherapeutically effective amount of one or more presently disclosedcompounds to a subject in need of treatment thereof. In someembodiments, the tumor cells express PSMA, such as prostate tumor cellsor metastasized prostate tumor cells. In other embodiments, a tumor maybe treated by targeting adjacent or nearby cells which express PSMA. Forexample, vascular cells undergoing angiogenesis associated with a tumormay be targeted. Essentially all solid tumors express PSMA in theneovasculture. Therefore, methods of the presently disclosed subjectmatter can be used to treat nearly all solid tumors including, but notlimited to, lung, renal cell, glioblastoma, pancreas, bladder, sarcoma,melanoma, breast, colon, germ cell, pheochromocytoma, esophageal, andstomach tumors. Also, certain benign lesions and tissues including, butnot limited to, endometrium, schwannoma and Barrett's esophagus, can betreated according to the presently disclosed methods.

Accordingly, in some embodiments, the presently disclosed subject matterprovides a method for treating a prostate-specific membrane antigen(PSMA)-expressing tumor or cell, the method comprising administering atherapeutically effective amount of compound of formula (I) to a subjectin need thereof:

wherein: Z is tetrazole or CO₂Q; each Q is independently selected fromhydrogen or a protecting group; n is an integer selected from the groupconsisting of 1, 2, 3, and 4; R is H or C₁-C₄ alkyl; L is a linkergroup; and X is H or a photosensitizer moiety; or a pharmaceuticallyacceptable salt thereof.

In particular embodiments, the linker group has the formula -L₁-L₂-L₃-,wherein each L₁, L₂, and L₃ can be present or absent and can be arrangedin any order, and wherein: L₁ is—NH—(CH₂)_(m)—[O—CH₂—CH₂—O]_(p)—(CH₂)_(q)—C(═O)—; L₂ is—NH—(CH₂)_(s)—C(COOH)—NH—; and L₃ is —(O═)C—(CH₂)_(t)—C(═O)—; wherein m,p, q, s, and t are each integers selected from the group consisting of1, 2, 3, 4, 5, and 6.

In some embodiments, the compound of formula (I) has the followingstereochemistry:

In more particular embodiments, the compound of formula (I) is selectedfrom the group consisting of:

In yet more particular embodiments, the photosensitizer moiety isselected from the group consisting of:

In some embodiments, the PSMA-expressing tumor or cell is selected fromthe group consisting of: a prostate tumor or cell, a metastasizedprostate tumor or cell, a lung tumor or cell, a renal tumor or cell, aglioblastoma, a pancreatic tumor or cell, a bladder tumor or cell, asarcoma, a melanoma, a breast tumor or cell, a colon tumor or cell, agerm cell, a pheochromocytoma, an esophageal tumor or cell, a stomachtumor or cell, and combinations thereof.

In other embodiments, the PSMA-expressing tumor or cell comprises abenign lesion or tissue.

In yet other embodiments, the benign lesion or tissue is selected fromthe group consisting of an endometrium, a schwannoma, and Barrett'sesophagus.

In further embodiments, the cell comprises a cell adjacent to or nearbya tumor or cell that expresses PSMA. In particular embodiments, the cellcomprises a vascular cell undergoing angiogenesis.

C. Method for Monitoring a Target Uptake or a Response to Therapy forTreating a PSMA-Expressing Tumor or Cell

In some embodiments, the presently disclosed subject matter provides amethod for monitoring a target uptake or a response to therapy fortreating a PSMA-expressing tumor or cell, the method comprisingadministering an effective amount of a compound of formula (I) to asubject in need of treatment thereof, and measuring a fluorescencethereof:

wherein: Z is tetrazole or CO₂Q; each Q is independently selected fromhydrogen or a protecting group; n is an integer selected from the groupconsisting of 1, 2, 3, and 4; R is H or C₁-C₄ alkyl; L is a linkergroup; and X is H or a photosensitizer moiety; or a pharmaceuticallyacceptable salt thereof.

In particular embodiments, the linker group has the formula -L₁-L₂-L₃-,wherein each L₁, L₂, and L₃ can be present or absent and can be arrangedin any order, and wherein: L₁ is—NH—(CH₂)_(m)—[O—CH₂—CH₂—O]_(p)—(CH₂)_(q)—C(═O)—; L₂ is—NH—(CH₂)_(s)—C(COOH)—NH—; and L₃ is —(O═)C—(CH₂)_(t)—C(═O)—; wherein m,p, q, s, and t are each integers selected from the group consisting of1, 2, 3, 4, 5, and 6.

In some embodiments, the compound of formula (I) has the followingstereochemistry:

In more particular embodiments, the compound of formula (I) is selectedfrom the group consisting of:

In yet more particular embodiments, the photosensitizer moiety isselected from the group consisting of:

D. General Definitions

Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.Particular definitions are provided herein for clarity. Unless otherwisedefined, all technical and scientific terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich this presently described subject matter belongs.

As used herein, the term “agent” refers to a non-peptide, small moleculecompound. More generally, the term “therapeutic agent” refers to anon-peptide, small molecule compound that has the potential of affectingthe function of an organism. A therapeutic agent may decrease, suppress,attenuate, diminish, arrest, or stabilize the development or progressionof disease, disorder, or condition in a host organism or subject.

By “cell substrate” is meant the cellular or acellular material (e.g.,extracellular matrix, polypeptides, peptides, or other molecularcomponents) that is in contact with the cell.

By “modifies” is meant alters. An agent that modifies a cell, substrate,or cellular environment produces a biochemical alteration in a component(e.g., polypeptide, nucleotide, or molecular component) of the cell,substrate, or cellular environment.

By “control” is meant a standard or reference condition.

By “disease” is meant any condition or disorder that damages orinterferes with the normal function of a cell, tissue, organ, organism,or subject.

The subject treated by the presently disclosed methods in their manyembodiments is desirably a human subject, although it is to beunderstood that the methods described herein are effective with respectto all vertebrate species, which are intended to be included in the term“subject.” Accordingly, a “subject” can include a human subject formedical purposes, such as for the treatment of an existing condition ordisease or the prophylactic treatment for preventing the onset of acondition or disease, or an animal subject for medical, veterinarypurposes, or developmental purposes. Suitable animal subjects includemammals including, but not limited to, primates, e.g., humans, monkeys,apes, and the like; bovines, e.g., cattle, oxen, and the like; ovines,e.g., sheep and the like; caprines, e.g., goats and the like; porcines,e.g., pigs, hogs, and the like; equines, e.g., horses, donkeys, zebras,and the like; felines, including wild and domestic cats; canines,including dogs; lagomorphs, including rabbits, hares, and the like; androdents, including mice, rats, and the like. An animal may be atransgenic animal. In some embodiments, the subject is a humanincluding, but not limited to, fetal, neonatal, infant, juvenile, andadult subjects. Further, a “subject” can include a patient afflictedwith or suspected of being afflicted with a condition or disease. Thus,the terms “subject” and “patient” are used interchangeably herein.

An “effective amount” of an agent refers to the amount of the agentsufficient to elicit a desired biological response or a measurabledifference when compared to a control. As will be appreciated by one ofordinary skill in the art, the absolute amount of a particular agentthat is effective for treating a disease, disorder, condition, or injurycan vary depending on such factors as the agent to be delivered, themanner of administration, the age, body weight, and general health ofthe subject, the desired biological endpoint, the desired therapeuticeffect, and the like. Ultimately, an attending clinician will decide theappropriate amount and dosage regimen. For example, an “effectiveamount” of an agent can be an amount sufficient to produce a measurableimage when the compound is used for imaging, or an amount sufficient toameliorate the symptoms of a disease when the compound is used fortherapy. One of ordinary skill in the art will further understand thatan effective amount of an agent can be administered in a single dose, orcan be achieved by administration of multiple doses.

As used herein, the terms “treat,” treating,” “treatment,” and the like,are used interchangeably and are meant to decrease, suppress, attenuate,diminish, arrest, the underlying cause of a disease, disorder, orcondition, or to stabilize the development or progression of a disease,disorder, condition, and/or symptoms associated therewith. The terms“treat,” “treating,” “treatment,” and the like, as used herein can referto curative therapy, prophylactic therapy, and preventative therapy. Thetreatment, administration, or therapy can be consecutive orintermittent. Consecutive treatment, administration, or therapy refersto treatment on at least a daily basis without interruption in treatmentby one or more days. Intermittent treatment or administration, ortreatment or administration in an intermittent fashion, refers totreatment that is not consecutive, but rather cyclic in nature.Treatment according to the presently disclosed methods can result incomplete relief or cure from a disease, disorder, or condition, orpartial amelioration of one or more symptoms of the disease, disease, orcondition, and can be temporary or permanent. The term “treatment” alsois intended to encompass prophylaxis, therapy, and cure.

As used herein, the terms “prevent,” “preventing,” “prevention,”“prophylactic treatment” and the like refer to reducing the probabilityof developing a disease, disorder, or condition in a subject, who doesnot have, but is at risk of or susceptible to developing a disease,disorder, or condition. Thus, in some embodiments, an agent can beadministered prophylactically to prevent the onset of a disease,disorder, or condition, or to prevent the recurrence of a disease,disorder, or condition.

Further, as used herein, the term “inhibit” or “inhibits” means todecrease, suppress, attenuate, diminish, arrest, or stabilize thedevelopment or progression of a disease, disorder, or condition, or theactivity of a biological pathway, e.g., by at least 10%, 20%, 30%, 40%,50%, 60%, 70%, 80%, 90%, 95%, 98%, 99%, or even 100% compared to anuntreated control subject, cell, or biological pathway. By the term“decrease” is meant to inhibit, suppress, attenuate, diminish, arrest,or stabilize a symptom of a disease, disorder, or condition. It will beappreciated that, although not precluded, treating a disease, disorderor condition does not require that the disease, disorder, condition orsymptoms associated therewith be completely eliminated.

The term “administering” as used herein refers to contacting a subjectwith a presently disclosed agent.

By “therapeutic delivery device” is meant any device that provides forthe release of a therapeutic agent. Exemplary therapeutic deliverydevices include tablets and pills, described below, as well as syringes,osmotic pumps, indwelling catheters, delayed-release andsustained-release biomaterials.

In certain embodiments, presently disclosed subject matter also includescombination therapies. Depending on the particular disease, disorder, orcondition to be treated or prevented, additional therapeutic agents,which are normally administered to treat or prevent that condition, maybe administered in combination with the compounds of this disclosure.These additional agents may be administered separately, as part of amultiple dosage regimen, from the composition comprising the presentlydisclosed compounds. Alternatively, these agents may be part of a singledosage form, mixed together with one or more presently disclosedcompounds in a single composition.

By “in combination with” is meant the administration of one or morepresently disclosed compounds with one or more therapeutic agents eithersimultaneously, sequentially, or a combination thereof. Therefore, acell or a subject can receive one or more presently disclosed compoundsand one or more therapeutic agents at the same time (i.e.,simultaneously) or at different times (i.e., sequentially, in eitherorder, on the same day or on different days), so long as the effect ofthe combination of both agents is achieved in the cell or the subject.When administered sequentially, the agents can be administered within 1,5, 10, 30, 60, 120, 180, 240 minutes or longer of one another. In otherembodiments, agents administered sequentially, can be administeredwithin 1, 5, 10, 15, 20 or more days of one another. Where the one ormore presently disclosed compounds and one or more therapeutic agentsare administered simultaneously, they can be administered to the cell oradministered to the subject as separate pharmaceutical compositions,each comprising either one or more presently disclosed compounds or oneor more therapeutic agents, or they can contact the cell as a singlecomposition or be administered to a subject as a single pharmaceuticalcomposition comprising both agents.

When administered in combination, the effective concentration of each ofthe agents to elicit a particular biological response may be less thanthe effective concentration of each agent when administered alone,thereby allowing a reduction in the dose of one or more of the agentsrelative to the dose that would be needed if the agent was administeredas a single agent. The effects of multiple agents may, but need not be,additive or synergistic. The agents may be administered multiple times.In such combination therapies, the therapeutic effect of the firstadministered compound is not diminished by the sequential, simultaneousor separate administration of the subsequent compound(s).

Following long-standing patent law convention, the terms “a,” “an,” and“the” refer to “one or more” when used in this application, includingthe claims. Thus, for example, reference to “a subject” includes aplurality of subjects, unless the context clearly is to the contrary(e.g., a plurality of subjects), and so forth.

Throughout this specification and the claims, the terms “comprise,”“comprises,” and “comprising” are used in a non-exclusive sense, exceptwhere the context requires otherwise. Likewise, the term “include” andits grammatical variants are intended to be non-limiting, such thatrecitation of items in a list is not to the exclusion of other likeitems that can be substituted or added to the listed items.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing amounts, sizes, dimensions,proportions, shapes, formulations, parameters, percentages, parameters,quantities, characteristics, and other numerical values used in thespecification and claims, are to be understood as being modified in allinstances by the term “about” even though the term “about” may notexpressly appear with the value, amount or range. Accordingly, unlessindicated to the contrary, the numerical parameters set forth in thefollowing specification and attached claims are not and need not beexact, but may be approximate and/or larger or smaller as desired,reflecting tolerances, conversion factors, rounding off, measurementerror and the like, and other factors known to those of skill in the artdepending on the desired properties sought to be obtained by thepresently disclosed subject matter. For example, the term “about,” whenreferring to a value can be meant to encompass variations of, in someembodiments, ±100% in some embodiments±50%, in some embodiments±20%, insome embodiments±10%, in some embodiments±5%, in some embodiments±1%, insome embodiments±0.5%, and in some embodiments±0.1% from the specifiedamount, as such variations are appropriate to perform the disclosedmethods or employ the disclosed compositions.

Further, the term “about” when used in connection with one or morenumbers or numerical ranges, should be understood to refer to all suchnumbers, including all numbers in a range and modifies that range byextending the boundaries above and below the numerical values set forth.The recitation of numerical ranges by endpoints includes all numbers,e.g., whole integers, including fractions thereof, subsumed within thatrange (for example, the recitation of 1 to 5 includes 1, 2, 3, 4, and 5,as well as fractions thereof, e.g., 1.5, 2.25, 3.75, 4.1, and the like)and any range within that range.

EXAMPLES

The following Examples have been included to provide guidance to one ofordinary skill in the art for practicing representative embodiments ofthe presently disclosed subject matter. In light of the presentdisclosure and the general level of skill in the art, those of skill canappreciate that the following Examples are intended to be exemplary onlyand that numerous changes, modifications, and alterations can beemployed without departing from the scope of the presently disclosedsubject matter. The synthetic descriptions and specific examples thatfollow are only intended for the purposes of illustration, and are notto be construed as limiting in any manner to make compounds of thedisclosure by other methods.

Example 1 Synthesis of YC-9

To a solution of 1 (0.5 mg, 0.70 μmol) in DMSO (0.1 mL) was addedN,N-diisopropylethylamine (0.005 mL, 28.8 μmol), followed byIRDye700DX-NHS (0.5 mg, 0.26 μmol). After 1 h at room temperature, thereaction mixture was purified by HPLC (column, Econosphere C18 5 μm,150×4.6 mm; retention time, 22 min; mobile phase, A=10 mMtriethylammonium acetate (pH 7.0), B=MeOH; gradient, 0 mins=5% B, 5mins=5% B, 45 mins=100% B; flow rate, 1 mL/min) to afford 0.4 mg (67%)of YC-9. ESI-Mass calcd for C₉₆H₁₃₈N₁₆O₃₅S₆Si₃ [M-2]²⁻, 1175.9, found1175.3.

PSMA Binding Affinity of YC-9:

The PSMA binding affinity of YC-9 was determined by using afluorescence-based PSMA binding assay and the K_(i) value was found tobe 0.2 nM.

In Vivo Imaging of YC-9:

In vivo imaging was done using the Pearl Impulse Imager with excitationwavelength of 685 nm and emission wavelength of 700 nm, as well as awhite-light overlay. For in vivo study, mouse with PSMA expressing(PC3-PIP) tumor and PSMA non-expressing (PC3-flu) tumor was injectedintravenously with 10 nmol of YC-9 images were acquired at 1 h, 6 h and24 h time points. Following the 24 h image, mouse was sacrificed bycervical dislocation and tumor, muscle, liver, spleen, kidneys andintestine were collected and assembled on a petri dish for imageacquisition.

As shown in FIG. 4, the in vivo imaging study of YC-9 showed itconcentrated selectively within the PSMA expressing tumor.

In Vitro Photodynamic Therapy:

PSMA expressing (PC3-PIP) and non-expressing (PC3-flu) cells wereincubated with no dye, IRDye700DX (100 nM), and YC-9 (100 nM) for 1 hrat 37° C. After washing twice with the media, cells were eitherirradiated with light (2 J/cm², 690 nm) or non-irradiated. Cell kill wasmeasured by XTT assay 24 hr post irradiation. Error bar representsstandard deviation (n=4). As shown in FIG. 5, YC-9 efficiently andspecifically kills PSMA-expressing cells in vitro.

Example 2 Synthesis of YC-6

PPa—NHS was synthesized according to literature method (J. Am. Chem.Soc., 2005, 127, 8376-8385). To a solution of 1 (1 mg, 1.4 μmol) in DMF(0.1 mL) was added triethylamine (0.005 mL, 35.9 μmol), followed byPPa—NHS (1 mg, 1.6 μmol). After 2 h at room temperature the reactionmixture was purified by HPLC (column, Econosphere C18 5μ, 150×4.6 mm;retention time, 30 min; mobile phase, A=0.1% TFA in H₂O, B=0.1% TFA inCH₃CN; gradient, 0 mins=0% B, 5 mins=0% B, 45 mins=100% B; flow rate, 1mL/min) to afford 1.3 mg (83%) of YC-6. ESI-Mass calcd for C₅₉H₇₇N₉O₁₃[M]⁺, 1119.6. found 1120.0.

PSMA Binding Affinity of YC-6:

The PSMA binding affinity of YC-6 was determined by using afluorescence-based PSMA binding assay and the K_(i) value was found tobe 1.2 nM.

In Vivo Imaging of YC-6:

Imaging studies with YC-6 were undertaken on the Xenogen IVIS 200system. FIG. 6 shows the whole body (left) and ex vivo organ (right)imaging of mouse with PSMA+PC3 PIP and PSMA-PC3 flu tumors at 24 h postinjection of 50 nmol of YC-6.

REFERENCES

All publications, patent applications, patents, and other referencesmentioned in the specification are indicative of the level of thoseskilled in the art to which the presently disclosed subject matterpertains. All publications, patent applications, patents, and otherreferences are herein incorporated by reference to the same extent as ifeach individual publication, patent application, patent, and otherreference was specifically and individually indicated to be incorporatedby reference. It will be understood that, although a number of patentapplications, patents, and other references are referred to herein, suchreference does not constitute an admission that any of these documentsforms part of the common general knowledge in the art.

International PCT Patent Application Publication No. WO/2013/082338 forHOMOMULTIVALENT AND HETEROMULTIVALENT INHIBITORS OF PROSTATE SPECIFICMEMBRANE ANTIGEN (PMSA) AND USES THEREOF, to Pomper et al., publishedJun. 6, 2013;

International PCT Patent Application Publication No. WO/2009/002529 forLABELED INHIBITORS OF PROSTATE SPECIFIC MEMBRANE ANTIGEN (PSMA),BIOLOGICAL EVALUATION, AND USE AS IMAGING AGENTS, to Pomper et al.,published Dec. 31, 2008.

International PCT Patent Application Publication No. WO/2010/108125 forPSMA-TARGETING COMPOUNDS AND USES THEREOF, to Pomper et al., publishedSep. 23, 2010.

International PCT Patent Application Publication No. WO/2010/014933 forPSMA-BINDING AGENTS AND USES THEREOF, to Pomper et al., published Feb.4, 2010.

Although the foregoing subject matter has been described in some detailby way of illustration and example for purposes of clarity ofunderstanding, it will be understood by those skilled in the art thatcertain changes and modifications can be practiced within the scope ofthe appended claims.

That which is claimed:
 1. A compound of formula (I):

wherein: Z is tetrazole or CO₂Q; each Q is independently selected fromhydrogen or a protecting group; n is an integer selected from the groupconsisting of 1, 2, 3, and 4; R is H or C₁-C₄ alkyl; L is a linkergroup; and X is a photosensitizer moiety; or a pharmaceuticallyacceptable salt thereof wherein the photosensitizer moiety is selectedfrom the group consisting of:


2. The compound of claim 1, wherein the compound has the followingstereochemistry:


3. The compound of claim 1, wherein the compound of formula (I) isselected from the group consisting of:


4. A fluorescence imaging agent comprising a compound of claim
 1. 5. Amethod for treating a prostate-specific membrane antigen(PSMA)-expressing tumor or cell, the method comprising administering atherapeutically effective amount of compound of claim 1 to a subject inneed thereof:

wherein: Z is tetrazole or CO₂Q; each Q is independently selected fromhydrogen or a protecting group; n is an integer selected from the groupconsisting of 1, 2, 3, and 4; R is H or C₁-C₄ alkyl; L is a linkergroup; and X is a photosensitizer moiety; or a pharmaceuticallyacceptable salt thereof.
 6. The method of claim 5, wherein the compoundof formula (I) has the following stereochemistry:


7. The method of claim 5, wherein the compound of formula (I) isselected from the group consisting of:


8. The method of claim 5, wherein the PSMA-expressing tumor or cell isselected from the group consisting of: a prostate tumor or cell, ametastasized prostate tumor or cell, a lung tumor or cell, a renal tumoror cell, a glioblastoma, a pancreatic tumor or cell, a bladder tumor orcell, a sarcoma, a melanoma, a breast tumor or cell, a colon tumor orcell, a germ cell, a pheochromocytoma, an esophageal tumor or cell, astomach tumor or cell, and combinations thereof.
 9. The method of claim5, wherein the PSMA-expressing tumor or cell comprises a benign lesionor tissue.
 10. The method of claim 9, wherein the benign lesion ortissue is selected from the group consisting of an endometrium, aschwannoma, and Barrett's esophagus.
 11. The method of claim 5, whereinthe compound of formula (I) treats the PSMA-expressing tumor or cell bytargeting adjacent or nearby cells which express PSMA.
 12. The method ofclaim 11, wherein the cell comprises a vascular cell undergoingangiogenesis.
 13. The method of claim 5, wherein the linker group isselected from the group consisting of -L₁-, -L₂-L₃-, and -L₁-L₂-L₃-,wherein: L₁ is —NH—(CH₂)_(m)—[O—CH₂—CH₂—O]_(p)—(CH₂)_(q)—C(═O)—; L₂ is—NH—(CH₂)_(s)—CH(COOH)—NH—; and L₃ is —(O═)C—(CH₂)_(t)—C(═O)—; whereinm, p, q, s, and t are each integers selected from the group consistingof 1, 2, 3, 4, 5, and
 6. 14. The compound of claim 1, wherein the linkergroup is selected from the group consisting of -L₁-, -L₂-L₃-, and-L₁-L₂-L₃-, wherein: L₁ is—NH—(CH₂)_(m)—[O—CH₂—CH₂—O]_(p)—(CH₂)_(q)—C(═O)—; L₂ is—NH—(CH₂)_(s)—CH(COOH)—NH—; and L₃ is —(O═)C—(CH₂)_(t)—C(═O)—; whereinm, p, q, s, and t are each integers selected from the group consistingof 1, 2, 3, 4, 5, and 6.